DISSERTATION RESEARCH:Sea level rise and vegetation regime shifts: implications for soil carbon storage and vulnerability in coastal wetlands

论文研究：海平面上升和植被状况变化：对沿海湿地土壤碳储存和脆弱性的影响

• 批准号: 1601524
• 负责人: John Kominoski
• 金额: $ 1.64万
• 依托单位: Florida International University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1601524&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Sea; level; rise

Coastal wetlands filter water, buffer the coastline from storms, provide important habitat and are globally important for the storage of carbon. Carbon storage in wetland soils can be for the long-term and influences whether wetlands will persist during sea level rise by increasing a change in sediment elevation. Climate change and local freshwater management are increasing the movement of saltwater into coastal freshwater wetlands, altering the conditions of the wetlands and causing shifts in the types of vegetation growing there. In many tropical and subtropical coastal wetlands, mangroves are replacing grass-dominated marshes, with uncertain effects on the capability of soils to store carbon. This is especially true of coastal wetlands, because of their sensitivity to sea level rise. The goals of this study are to identify changes in the storage of carbon in wetland soils and releases to the atmosphere of the gases carbon dioxide and methane that occur as coastal wetland change from marshes dominated by grasses to mangrove forests. The research findings will provide valuable information for the conservation and restoration of the Florida Everglades locally as well as coastal wetlands throughout the world. Furthermore, the findings will provide a broader understanding of plant and soil interactions and ecosystem function in a changing world. The project will provide hands on scientific experience identifying and growing wetland plants and restoring urban coastal wetlands for local high school students during "Marsh Mangress", an outreach activity at Florida International University. This activity will also provide undergraduate students with laboratory and field experience at a majority minority institution. This research will utilize a vegetation gradient in 10,000 Islands National Wildlife Refuge in Naples, FL in which sea level rise and freshwater manipulation have driven vegetation change and mangrove encroachment, in order to understand how changing abiotic conditions and vegetation state change alter carbon storage through time. Changing carbon storage will be measured as current organic carbon stocks (above and belowground biomass, soil carbon content), inputs (root productivity, sediment surface accretion) and carbon losses (breakdown rates of organic carbon, gas flux measurements), past carbon sequestration rate (radiometric soil dating), and potential future rates of carbon loss (reciprocal transplant of organic matter to represent freshwater restoration or continuing saltwater intrusion). Specifically, the goals of this project are to: 1) Identify differences in carbon storage, accretion, and gas flux among wetlands dominated by brackish marsh, saltwater marsh, and mangrove-dominated vegetation communities. 2) Determine which abiotic and biotic mechanisms drive differences in soil carbon dynamics among wetland types. 3) Quantify the effect of time since mangrove establishment on soil carbon storage, accretion and gas flux by establishing a chronosequence of mangrove encroachment based on soil dating and historic aerial photography.

沿海湿地过滤水，缓冲海岸线从暴风雨来提供重要的栖息地，对于碳的存储至关重要。湿地土壤中的碳存储可以长期使用，并影响湿地在海平面上是否会通过增加沉积物高度变化而持续。气候变化和当地的淡水管理正在增加盐水向沿海淡水湿地的运动，改变湿地的状况，并导致那里种植的植被类型的变化。在许多热带和亚热带的沿海湿地中，红树林正在取代草的主导沼泽，对土壤储存碳的能力的影响不确定。沿海湿地尤其如此，因为它们对海平面上升的敏感性。这项研究的目标是确定碳土壤中碳的储存变化，并释放到气体二氧化碳和甲烷大气中，这是因为沿海湿地从沼泽地从沼泽地转变为沼泽地，从草沼泽到红树林。研究结果将为佛罗里达大沼泽地以及世界各地的沿海湿地提供有价值的信息。此外，这些发现将在不断变化的世界中对植物和土壤相互作用以及生态系统功能提供更广泛的了解。该项目将提供科学经验，以识别和种植湿地植物，并在佛罗里达国际大学的推广活动“ Marsh Mangress”期间为当地高中生恢复城市沿海湿地。这项活动还将为本科生提供大多数少数族裔机构的实验室和现场经验。 这项研究将利用佛罗里达州那不勒斯的10,000个岛屿国家野生动物保护区的植被梯度，其中海平面上升和淡水操纵驱动了植被的变化和红树林侵占，以了解如何变化的非生物条件和植被状态变化改变碳的储存时间。不断变化的碳存储将以当前的有机碳储备（地面和下面的生物量，土壤碳含量），投入（根生产率，沉积物表面积聚）和碳损失（有机碳的破坏速率，气体测量率），碳固化速率（辐射量的土壤损失）（辐射率损失）（碳固定速度）（碳固定率）（频道的未来率）（碳替代率）盐水入侵）。具体而言，该项目的目标是：1）确定湿地中以咸淡的沼泽，盐水沼泽和红树林主导的植被群落为主的湿地中碳储存，积聚和气体通量的差异。 2）确定哪种非生物和生物机制驱动湿地类型的土壤碳动态差异。 3）通过建立基于土壤约会和历史航空摄影的红树林侵占，量化了红树林建立以来对土壤碳储存，积聚和气体通量的影响。